• Mar 1, 2026 shifrin multivariable mathematics rtial f}{\partial x} \quad \text{and} \quad \frac{\partial f}{\partial y} \] represent the slopes of the tangent lines to the surface along the \(x\) and \(y\) directions, respectively. They form the basis for: Tangent planes, which approximate the surface locally. By Krista Paucek
